Solved! I moved into home with an existing speakers in the ceiling and I can't get them to work.

[AudioHell]

I found some papers in the house that identify the speakers as Monitor Audio CS160. There is also a receipt referencing Crestron as the installer but all there is is a mass of cables spilling from my wall. I tried buying a Sonos Amp and plugging the cables labeled as the living room speakers in but no dice.

 

[Sonic Illusions]

Here's an old trick that works for me every time. Grab any 1.5 volt battery and hold one speaker wire against one terminal...doesn't matter which one...then tap the other wire on the other terminal. You'll hear a popping sound from the speaker IF you've found the + and - cable for that speaker. Do this for all to verify they function. You may need an assistant to be where you can't hear the speaker. Verify the labels or make your own.